In some applications, turn-on of power switches is performed with Zero Voltage Switching (ZVS). Using ZVS in, for example, power converters can increase efficiency when compared to conventional hard switching power converters. A power converter using ZVS may eliminate drain circuit switching losses and some gate circuit switching losses. A power converter using ZVS may also eliminate rectifier reverse recovery effects and, in some cases, channel conduction losses.
ZVS turn-on is often achieved by current commutation to a diode in parallel with the switch being turned-on. In some cases, the flow of the current in the diode may clamp the voltage across the switch to a value of approximately 1V, which may be sufficiently close to zero to be considered a zero crossing point. In some instances the voltage across the switch may be negative. Near zero voltage during the turn-on results in zero turn-on losses or near zero turn-on losses, which in combination with reduction in turn-off losses results in very low switching losses and hence a possibility of achieving high operating frequencies.